<template>
    <div class="demo">
        <h1>I am {{ op }}</h1>
    </div>
</template>

<script>
    export default {
        name:'My',
        data() {
            return {
                op: 'happy',
            };
        },
    }
</script>

<style>
    .demo{
        background: greenyellow;
    }

</style>